ApoA-I Tangier and apoA-II Tangier were purified to homogeneity from a homozygous patient with Tangier disease. ApoA-I Tangier differed from apoA-I isolated from normal subjects in amino acid composition, apparent molecular weight on SDS gel electrophoresis, and heterogeneity of isoforms on two-dimensional polyacrylamide gel electrophoresis. ApoA-II Tangier was identical in physical-chemical properties to apoA-II from normal subjects. ApoE2, E3, and E4 have been isolated in homogeneous forms and their physical-chemical, and metabolic properties analyzed. ApoH has been purified, and shown to be identical to Beta 2-glyco-protein-I. ApoH has a high content of cystine and proline, and unusual molecular properties due to its amino acid composition. Human PTH (1-84) has been synthesized by the solid-phase method. The synthetic hormone had a similar biological activity and immunological properties to the native hormone.